Carburetor



Dec. 27, 1955 R. F. BRACKE 2,728,564

CARBURETOR Filed April 3, 1952 CARBURETOR Robert F. Bracke, Arlington Heights, lll., assignor, by

mesne assignments, to MallTool Company, a corporation of Illinois Application April 3, 1952, Serial No. 280,322 2 Claims. (Cl. 261-69) My invention relates to carburetors and is more particularly directed but lnot limited to a carburetor `for an engine having a coustantpower demand such as the free piston engine Yof a -gasoline power operated hammer.

An object of my invention isto provide `a simple, efficient, and inexpensive carburetor which `will automatically `and effectively compensate for dierences in head of fuel in a supply tank to Vwhich the carburetor is connected.

Another object of my invention is to provide a carburetor having a new and improved fuel valve.

Another object of my invention is to provide a 'carburetor having new and 4improved fuel control means.

Other objects and advantages will become apparent as the description proceeds.

The single figure Aof the drawing is a general vertical, sectional, elevational view Vof a preferred embodiment 0f my invention.

Referring to the drawing it will be seen that my invention comprises a body- 10 having an air passage 12 therethrough. This air passage has an inlet end 14 which may be provided with an air cleaner 16 if desired, such air cleaner being attached to the body by means of bolts 18. The outlet end 2l) of the air passage 12 is in communication with an intake manifold 22 or directly with the intake port of an engine to which the carburetor is attachedby suitable bolts or in any other desired manner.

A Venturi 24 is located in the air passage '12 and a choke valve 26 is provided adjacent Vthe inlet end' of this airpassage. It vwill be understood that this choke valve 26 may be providedV Withany usual controls for adjusting the choke between the full line position and dotted line position and all intermediate points. The airI passage 12 is also provided with a drain opening 28 which serves to prevent flooding. Since the carburetor is designed for use with an engine having a constant power demand, no throttle valve is provided.

Fuel is supplied to the carburetor through a pipe 30 connected with a fuel tank or any other suitable source of supply. The incoming fuel ows through a passage 32 into the central portion of a lter chamber 34 containing a cylindrical filter 36 clamped to the inlet fitting 38 by a bolt 40. By removing inlet fitting 38 the filter 36 may be readily inspected and replaced if desired.

Fuel which is passed through the lter 36 ows through a passageway 42 to the upper end of a valve chamber 44 partly defined by the body 10 and partly by a valve seat member 46 threadedly secured to the body 10 as indicated at 48. A gasket 50 is preferably clamped between the upper end of the member 46 and an adjacent shoulder provided by the body 10 to effect a fluidtight seal therebetween. The member 46 provides a valve seat 52 and a perforated valve retainer 54 spaced from the seat 52. A ball valve 56 is located between the seat 52 and retainer 54 and normally engages the seat 52 when the engine is not running to prevent ow of fuel therepast. It will be noted that the ball valve 56 phragm 2 is not actedupon by any spring or other restricting memberv and. is free to rotate as fuel :ows therepast. fSuch rotation causes'the valve to wipeitself and .its seat 'free of any dirt deposited' thereon and' is important in main- `taining the valve in perfect operating condition at all times.

lower' portions artdis clampedbetween the body 10 and a cover 66 secured to `the body by screws 68.

The 'diaphragm '64 is made. of material which is impervious to gasoline and water and which is capable of exing in response to derentials `in pressures on 0pposi'te sid-es thereof. The central portion of the dia- '64 is provided with metal plates 70 and 72 clamped to opposite sides of the diaphragm by a rivet '74. This rivet engageslthe .lower end of push rod 58 kandtransmits valve opening force vthereto when the diaphragm exes upwardly. A spring 76 confined between diaphragm plate70 ,and a shoulder provided by valve seat member 46 urges the centrallportion of lthe diaphragm downwardly.

My novel carburetor isprovided with a single jet' 78 located in the Venturi'24.. Fuel from the upper portion of fthe diaphragm chamber is drawn upwardly through Apassageway 80 yto a needle valve 4chamber'82 Yand thence tlowsthrough passageway'84 to the 'dischargejet 78. A needle valve 8'6 controls. communication between chamber 82" and passageway 84 and .can be adjusted to regulate thefilow of fuelby turning. knob 88. Sealing glands 90.and' 921 prevent leakage of air into the needle :valve ,chamber 82 and friction between the needle valve and its cooperatingparts retain the.valve in adjusted position.

.1I have provided-what is commonly known as a tickler mechanism for manually opening the fuel valve 56. This tickler mechanism comprises a rod 94 having a. cap 96 secured to its lower. end. A spring '918zcon'ned between .this 'cap `and apart of the cover '66 holds the rod 194 .in the retracted-position shown. In this position the venlarged' vupper end. 100 serves .to limit withdrawal Aofthe rod and is `spaced below the rivet 74' of the diaphragm 64. By pushing upwardly on the cap 96 the central portion of the diaphragm and push rod 58 are moved upwardly to open the fuel valve 56.

This tickler mechanism also provides communication between the lower side of the diaphragm 64 and atmosphere. The push rod 94 ts loosely in bore 102 of cover 66. The space around the rod 94 and the transverse slot 104 provide such communication so that the lower side of the diaphragm is always exposed to atmospheric pressure.

In starting an engine provided with my novel carburetor the choke valve 26 would normally be moved t0 substantially closed position and the mixture delivered to the engine could be further enriched by pressing upwardly on the tickler cap 96 to manually open the fuel valve 56. The engine is then cranked or otherwise turned over and this creates a ow of air through the air passage 12 and also a suction at the jet 78, thereby producing a ow of fuel to this jet and a discharge of this fuel into the air flowing to the engine intake. As soon as the engine has started, the tickler cap 96 would normally be released and the fuel valve held open solely by the suction created on the upper side of the diaphragm 64 by engine operation, such suction being transmitted to the upper side of the diaphragm through jet 78, passageway 84, needle valve chamber 82, and passageway 80. As soon as the engine warms up, the choke valve 26 is returned to fully open position.

Since the engine is of the constant demand type, it will be readily apparent that the suction created above the diaphragm 64 would be constant if the pressure under which the fuel is supplied to valve chamber 44 remains constant. However, this latter pressure varies with the -close tolerances are readily available on the open market and it is a simple matter to make the valve seat 52 accurate. The other parts may all be readily manufactured to conventional tolerances by high speed production equipment and methods, and readily assembled to produce the completed carburetor.

While I have illustrated and described only a single embodiment of my invention, it is to be understood that my invention may assume other forms and that my invention includes all variations, modifications, and equivalents coming within the scope of the appended claims.

I claim:

1. A carburetor comprising a body having an air passage therethrough, a Venturi in said passage, a fuel jet discharging into said Venturi, means providing a fuel inlet for said carburetor, passageways including a dia phragm chamber and a valve chamber above said diaphragm chamber connecting said fuel inlet with said fuel jet, a restricted vertical passageway connecting said diaphragm and valve chambers, a valve in said valve chamber including a free ball resting on a seat formed at the mouth of said restricted vertical passageway, said ball being held on said seat by gravity, a diaphragm horizontally disposed in said diaphragm chamber having its under side exposed to atmosphere, and a movable rod supported on said diaphragm to be actuated there by and extending through said vertical passageway and loosely fitting therein, said movable rod extending to said ball valve connecting said diaphragm and said ball valve, whereby when said diaphragm is displaced said movable rod unseats said ball valve allowing fuel to pass through said valve chamber, the restricted vertical passageway around said movable rod, and said diaphragm chamber to said fuel jet, and when said diaphragm returns to its original position gravity reseats said ball valve preventing the ow of fuel to the fuel jet.

2. A carburetor comprising a body having an air passage therethrough, a Venturi in said passage, a single fuel jet discharging into said Venturi, means providing a fuel inlet for said carburetor, a diaphragm chamber, passageways including a valve chamber disposed above said diaphragm chamber connecting said fuel inlet with said diaphragm chamber, a restricted vertical passageway connecting said diaphragm and valve chambers, a fuel valve in said valve chamber including a free ball resting on a seat formed at the mouth of said restricted vertical passageway, said valve being gravity actuated to seal the mouth of said passageway, a diaphragm in said diaphragm chamber having one side exposed to fuel therein and the other side exposed to atmosphere through a bore in said body, a movable rod supported on said diaphragm connecting said diaphragm and said fuel valve, said movable rod extending through said restricted vertical passageway and loosely fitting therein, and a passageway extending from said diaphragm chamber to said fuel jet to displace said diaphragm in accordance with l the pressure in said Venturi, whereby when said diaphragm is displaced said movable rod unseats saidfuel valve allowing fuel to fiow from said fuel inlet through said fuel valve and said restricted vertical passageway around the movable rod therein to said diaphragm cham@ ber and to the fuel jet, and when said diaphragm returns to its original position gravity reseats said valve sealing the mouth of said restricted vertical passageway and preventing the flow of fuel to the diaphragm chamber and the fuel iet.

References Cited in the file of this patent UNITED STATES PATENTS 1,787,230 Atkins Dec. 30, 1930 2,125,886 Chandler Aug. 9, 1938 2,141,365 Schuttler Dec. 27, 1938 2,183,636 Berry Dec. 19, 1939 2,491,760 Orr Dec. 20, 1949 2,537,347 Hieger et al. Jan. 9, 1951 2,569,377 Hans Sept. 25, 1951 2,580,294 Griifon Dec. 25, 1951 2,610,044 Wirth et al Sept. 9, 1952 2,662,758 Anderson et al Dec. 15, 1953 

